Abstract

This paper describes the concentration of selected
heavymetals (Co, Cu, Ni, Pb, and Zn) in theMamut
river sediments and evaluate the degree of contamination
of the river polluted by a disused copper mine. Based on
the analytical results, copper showed the highest
concentration in most of the river samples. A comparison
with Interim Canadian Sediment Quality Guidelines
(ICSQG) and Germany Sediment Quality Guidelines
(GSQG) indicated that the sediment samples in all the
sampling stations, except Mamut river control site (M1),
exceeded the limit established for Cu, Ni, and Pb. On the
contrary, Zn concentrations were reported well below the
guidelines limit (ICSQG and GSQG). Mineralogical analysis
indicated that theMamut river sediments were primarily
composed of quartz and accessory minerals such as
chalcopyrite, pyrite, edenite, kaolinite, mica, and muscovite, reflected by the geological character of the study area. Enrichment factor (EF) and geoaccumulation index (Igeo) were calculated to evaluate the heavy metal pollution in river sediments. Igeo values indicated that all the sites were strongly polluted with the studied metals in most sampling stations, specifically those located along the Mamut main stream. The enrichment factor with value greater than 1.5 suggested that the source of heavy metals was mainly derived from anthropogenic activity such as mining. The degree of metal changes (Î´fold) revealed that Cu concentration in the river sediments has increased as much as 20 to 38 folds since the preliminary investigation conducted in year 2004.